Change of Heart
by Evil Cosmic Triplets
Summary: Scott asks Derek to keep an eye on Stiles, promising that he'll be part of his pack in return. A silent vigil beneath Stiles' window quickly turns into something else when Derek senses that something's wrong with the teen.


**Disclaimer: **I do not own the characters in this work of fiction, and no profit, monetary or otherwise, is being made through the writing of this.

**A/N:** Written for cottoncandy_bingo square, Kissing Away Pain. Animegirl1129 suggested this fandom for the square, and helped me through some of the difficulties. Taking liberties with werewolf lore and real wolf habits, and with plot as well, because it's not solidly backed with background, just kind of jumps into the story, and does not explain the whats or whys, but, that's the point of this profile - experimentation on all fronts. Enjoy, and please leave me some feedback. Thanks.

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Derek paces beneath Stiles' window, wondering, not for the first time, why he'd agreed to Scott's terms. If he hadn't, he'd be somewhere else right now, not listening to Stiles shift around in his bedroom doing who knows what.

He can hear Stiles' heart. It's beating a little quicker than normal. It bothers Derek that he knows this, and he frowns, because he shouldn't know the rhythm of Stiles' heartbeat. Means he's much too close to the human.

As he turns to make another pass beneath the teen's window, a sound causes Derek to pause mid-step. It isn't an overly loud, nor is it an exceptionally startling, sound. As a matter-of-fact, it's a barely there noise which hardly garners any interest whatsoever, yet Derek tilts his head toward the darkened window, and listens.

His frown deepens as he tries to categorize the sound that he's hearing, because, at first it doesn't make sense, not coming from Stiles. Stiles might be human, but he is strong and brave, even if he doesn't always let on that he is. He uses humor the way that Derek uses anger – to shield, to mask, to motivate.

When changing the angle of his head does nothing to alleviate the odd noise, but rather amplifies it, because he's now straining every muscle in his body to hear what his brain is finding difficult to comprehend, Derek resumes his pacing. He thinks that Stiles might tease him over his confusion, say something, like: 'Does not compute,' in a robotic voice. And that bothers him even more, because if he shouldn't know what Stiles' normal heartbeat – three and a half seconds slower than it is at present – he most definitely should not be able to hear the teen's sarcastic voice in his head like some snarky Jiminy Cricket.

When the sound starts to grate on his nerves, Derek increases his pacing, his hands clenching and unclenching in loosely held fists. His own heartbeat is steadily increasing as each half-second ticks away, and the sound of Stiles' soft, half-sobs continue to anger him. Why doesn't the teen just stop whatever the hell he's doing that's causing the pain? Derek wonders, and he grits his teeth, feels his jaw lock into place.

His muscles are strung tauter than a tightrope, and his head's at an awkward angle, ear pointed steadfastly toward Stiles' window, when he simply snaps. Stiles' off-pace heartbeats, coupled with his quiet, tempered soughs of pain drive Derek to do what he's determined, at the onset of this protective vigil (a promise to Scott in exchange for the teen's help with pack dynamics), he wouldn't do.

Derek feels the shift when he crouches low to the ground. And that's a surprise, because he's usually in more control of himself than that. He springs upward, and, without much effort at all, lands on a first, and then a second tree limb. The air, stagnant and heavy with humidity, swirls around him, as he moves. He lands on his haunches, on the little outcropping of roof just outside of Stiles' bedroom window, and in the same movement, he slides in through the open window, landing deftly on the balls of his feet.

Derek's eyes don't need much time to adjust from the brightness of the moon outside to the dimness of Stiles' room. He shifts back to his human form so that when he reveals himself to Stiles, he doesn't frighten the teen any more than his sudden appearance will.

The teen's kneeling in the center of his bed, and, so helplessly human, he's unaware of Derek's presence. Now that Derek can see what's been causing Stiles to make that unnerving sound, he's knelt behind the boy in a quarter of a heartbeat, fingers lightly touching the dark bruises and paper-thin cuts that cover Stiles' back in a mishmash of black, blue, red and purple.

The reason for the now almost soundless, tearless crying is that Stiles has been painstakingly working his tee-shirt up and over his back. It's only halfway toward his shoulder blades, and Derek can see dried blood, a russet color, where the once white tee-shirt has been clinging to the teen's marred skin.

Stiles is biting his lower lip and his eyes are scrunched tightly closed. Judging by the distinct lack of an acerbic comments sent his way, Stiles is still unaware of Derek's presence, in spite of the fact that the werewolf's fingers are now ghosting over the lash marks, tracing each and every cut that he can see, and his knees are flush against Stiles' backside.

The removal of the cotton fabric from Stiles' scored skin has reopened the wounds, which, given their thinness, wouldn't have taken all that long to close up when they were first inflicted. Derek places his palm on one of the worst of the bruises that the hiked up tee-shirt reveals, and that's when Stiles becomes aware of him – sharp intake of breath, rocketing heartbeat, and frantic scrabbling, on hands and knees, toward the head of his bed.

"Hold still," Derek growls, and he grasps Stiles' hips, not hard enough to bruise, but enough to keep the teen from continuing to flee from him.

He doesn't mean to growl or add to Stiles' pain, but right now, seeing how hurt Stiles really is, he can't help it – he responds like an alpha wolf caring for one of his pack. A weaker member, not lesser. Physical weakness does not necessarily equate lowly status.

Like a pregnant she-wolf, brutal in her own right, a pack member who is weaker than the others is often at the center of the pack's attention, gaining their collective care and protection. Unless, of course, the weakness is due to a sickness that cannot be cured. Then the member is shunned, sometimes even killed by the pack.

But, Stiles is more like a she-wolf, not that he's what Derek would consider to be feminine. On the contrary, it's Stiles' fierce tenacity – his willingness and ability to face down, and bring dangerous 'predators' to submission to protect the others in the pack – that reminds Derek of his mother and his sister.

Wolves don't handle their injured kits or mates with gentleness and coddling, but with rough, coordinated movements borne of instincts built for survival, and with strident commands. Both of which Derek defaults to now as his fingers dig into Stiles' hips, shifting them back toward him, and laying the teen flat on his stomach with sure movements which are made to be efficient rather than pain free. He straddles the teen's hips, to keep him in place

Derek ignores Stiles' whimpered pleas for him to, 'Stop,' when he bends so that his face is over the boy's back, because if he doesn't do this, the wounds on the teen's back will become severely infected. But, before that, they will fester and cause Stiles even more pain. And then, provided that Stiles survives the infection, they'll scar, leaving thin bands of whitened, puckering skin crisscrossing his back.

Derek knows that what he's about to do will cause Stiles excruciating pain, but there's nothing for it. If he takes his time carefully peeling the shirt from the teen's back, it will only prolong the boy's suffering.

"Let me go," Stiles' voice is soft, "please. I …I…"

Derek holds his breath, hands clutching the hem of Stiles' blood-stained tee, poised, ready to tear the shirt from the cut-littered back in one swift movement that is bound to hurt.

"Derek doesn't need to know."

The whispered words cause Derek to shift back into wolf form again, and he waits and listens, willing Stiles to tell him who and what so that he can hurt, kill, destroy.

"And I'm never going to say, yes, no matter what you do to me," Stiles says, and his voice gains strength as he speaks. "You can cut me into a thousand pieces, beat me to within an inch of my life, but I will never take the bite from you, Peter. I won't help you become top dog again. You can go to hell."

The anger, the revelation, surprises Derek, as does Stiles's pushing up on his elbows and struggling to upend him from his seated position on the back of the teen's legs. The teen's switch from begging to rage is a welcome one – means that Stiles is not beaten – but it also makes what Derek's trying to do for him that much more difficult.

While Stiles is not as strong as him, he's putting up a fight, and his wriggling and squirming is not helping. Actually it's making things worse. Much, much worse. Derek only hopes that, in his current state of confusion, Stiles is unaware of his not so small predicament.

Derek shifts his weight, hoping to ease some of the friction between himself and Stiles, because his not so small problem is growing the more that Stiles wiggles around in an attempt to free himself. Derek is well aware of the benefits of engaging in sexual acts to help relieve pain – been there, done that – but he doubts that Stiles is in the right frame of mind to see the advantages of it, given that he still thinks Derek is Peter.

And, that should be enough to make him soft, the thought of Peter, but he's still hard and swelling and if Stiles doesn't stop moving, right about now, Derek's going to have to excuse himself and come back later.

Derek applies pressure to the back of Stiles' neck, pushing his face down into the mattress. He presses his nose to Stiles' ear, exhales, and snarls. "Hold still."

Stiles shivers, but stops moving.

Derek's lips brush against Stiles' earlobe. "I'm trying to help you."

Stiles makes one last, valiant effort to throw Derek off, bucking upward and crying out in pain, but then Derek shoves with the hand he's got at the base of Stiles' head and the teen goes limp. If it wasn't for the wet, breathy sounds coming from Stiles, Derek would've feared that he'd accidentally killed the boy.

"Hold still," he commands in a voice that's not wholly alpha, because he's hard and Stiles is right there, and there's only the barest hint of a whimper in his command. Just a slight tremor in his voice that communicates his want, his need.

"Let me, just, let me…" Derek's never been this lost before, not with Kate. Were it Kate beneath him right now, his problem would already be halfway toward being resolved. But this isn't Kate, and, if anything, his problem has grown, even with Stiles lying so still.

"Derek?" Stiles's breath hitches and the teen relaxes.

"Yeah." The single syllable is all that Derek can manage, and he shifts off of Stiles, kneeling beside him.

His hand's still in place at the base of the teen's neck, applying just the hint of pressure, fingers now massaging the taut muscles that lie beneath them. This isn't about domination, it's about protection, healing, maybe even love.

And that's another problem, because Derek does real good with anger. He's familiar with it and it with him. But he sucks at love. Always has. He'd blame Kate for it, for the broken trust, the vulnerability, the messing with his head, but, he can't remember a time when he was good at love. Hate, anger, distrust – as far back as he can remember, they've been there, guiding him, dogging his every step.

"Sorry." The word, spoken in this context, doesn't make sense. Derek ignores it.

Derek rubs a thumb along one of the exposed cuts, and he aches when Stiles flinches.

"Not going to hurt you," he promises, head already dipping low toward Stiles' back, lips tingling.

"What," Stiles swallows his next word, "what are you going to do?"

Fear. It's tangible. Derek can taste it in the air – brackish and pungent, like garlic. He can hear it in the way that Stiles is trying, unsuccessfully, to even out his breathing, and the teen's stilted heartbeat – start, stop, start, stop.

"I'm going to heal the cuts on your back," Derek says, eyes focusing like lasers on the myriad of red slashes that he can see. The tee-shirt is still very much an obstacle.

"This next part is going to hurt," he warns, even as he rips the ruined shirt from hem to collar, rending shirt from skin, breaking open scabs, causing blood to flow freely, and Stiles to muffle a scream against the mattress.

Stiles turns his head to the side and takes big heaving gasps of air through his mouth. "You lied," he says ten and a half heartbeats later, "prom'sed wd'nt h'rt."

His eyes are screwed shut, and his fingers are twisted in the sheets.

"Sorry." The word feels foreign coming from his lips, sounds strange, and Derek tugs the tee-shirt from beneath Stiles' chest, tossing it to the floor. He'll burn it later. Anything with Stiles' blood on it should not be left lying around.

"Sh'd know b'tr," Stiles mumbles, "w'rewolves always h'rt on Stiles."

For this next part, Derek doesn't warn Stiles, because there aren't words for what he's about to do. And if he does warn Stiles, he's half-afraid that the teen won't let him do what needs to be done.

He keeps his hand at the back of Stiles' neck, because this will not work if the teen moves and he dips his head down toward Stiles' exposed back, licks his lips, and then hovers over a particularly nasty-looking cut, thumbing along the edge of it. This one's already started to redden with infection, and there's a bead of blood sitting smack dab in the middle of it.

When his lips, warm, pulsing with need, brush over the top of the wound, Stiles stops breathing, he stiffens slightly, and his heart starts to hammer in his chest. The teen's toes curl into the sheets, and his fists pound into the mattress.

"Wh...what are you doing?" Stiles asks when he can breathe again, but his heart rate doesn't slow any, and he flattens his hands against the mattress, digs his fingers into the sheets.

Derek works his tongue into the groove of the wound, laps at the blood, wraps his lips around the edges of it, as though to cinch it together. And it works; the edges bind together, Derek's saliva acting as a kind of medical glue. He's only done this once before, and never with so many cuts.

Most werewolves have the power to tamper with pain. They can, though skin-on-skin contact, take on the pain of another. Derek, however, was not like most werewolves. He'd been born with the ability to, not just ease pain, but also to heal.

He'd discovered it early on, when he was just a toddler, and a baby bird had fallen out of its nest. Though his father had tried to explain that the bird was dead, Derek focused his attention on it, touched it and pictured it whole and healthy and flying. The baby bird had come back to life chirping and his father had made him promise to keep what he could do a secret.

He had until Kate. The cut had gone from the inside of her elbow to the palm of her hand. He'd thought that he was going to lose her. If he'd have known what she was, what she would do to his family, he'd have left her to die.

But, hindsight screwed with the head, made you second guess your actions, made you think that what had been right in the past was wrong now that you could see the full ramifications of your actions. Hindsight was shitty, and rarely made anyone feel good.

Derek's not planning to look back on this with anything resembling regret, because Stiles isn't Kate. He isn't cold, heartless, calculated; he's Stiles, the kid was an open book, had a heart two sizes too big, and loyalty that would no doubt one day be the death of him (Derek's not letting that happen if he can help it).

Derek moves onto the next cut. Tongue first, and then lips that suction around the thin slash in what, in any other circumstances, would be considered a kiss. Stiles gasp, arches his back a little when Derek moves onto another cut.

"Derek?" Stiles' voice is shaky, uncertain. "Are you…" he swallows. "Are you kissing me?" He squirms a little, loosening the hold that Derek has on him, and cranes his neck. Stiles takes a quick, shocked inhale, and Derek raises his eyes, his lips are wrapped around the outer edges of another cut, catches Stiles looking at him – the teen's pupils are blown wide, and Derek reads more than just shock in them.

"You _are _kissing me," the teen breathes out, and he bites his lip, lets go of the hold that he has on the bed sheets and reaches back to capture Derek's wrist and pull alongside him, for what, Derek doesn't know, but the feel of Stiles' fingers on his pulse points is like the touch of fire.

"You _are_ kissing me," Stiles repeats, and there's a touch of awe and confusion in his voice, his mouth turns downward in a frown. "Why are you kissing me Derek?"

Derek narrows his eyes at Stiles, holds the teen's puzzled gaze with his own as he works his tongue into the hollow of another thin slash mark. Before he sutures the broken skin together with a kiss, he manages to grunt out a partial sentence, "Healing you," and then he breaks eye contact and then binds the cut together with a kiss.

"Healing me with kisses?" Stiles' voice breaks on the final syllable, like a hormonal pre-teen, and he swallows. "The big, bad werewolf is healing me with kisses?"

Stiles lowers his head, but doesn't release Derek's wrist. If anything, his fingers seem to tighten their grip, wrenching a moan from Derek.

Stiles blinks, his dark lashes contrast sharply with the paleness of his cheeks, usually flush with color. Derek wants to bring color back to Stiles' cheeks, infuse them with the blush of health, maybe something more.

He closes his eyes, concentrates on an image of Stiles: pupils wide as dimes, thick lashes fanning freckled cheeks, rosy and glowing, heated, the edges of his mouth quirked upward in a smile as laughter bubbles forth from his lips. He pictures Stiles' back, blemish free, focuses on the likeness of Stiles in his head, wills it to happen, like with the bird, and Kate, except he wants this more.

Derek moves his tongue and lips along Stiles' back, letting the picture in his head guide him, because right now he can't open his eyes. Doesn't need to. He can _see_ Stiles healed and whole. Derek's heartbeat quickens, matching Stiles' accelerated pace, beat for frantic beat.

Slight tremors wrack Stiles' body, Derek can feel them through his lips and tongue, and, in spite of the fact that his small problem has grown proportionately with the addition of Stiles' blood to his diet, he straddles Stiles' legs, pinning him down. The tremors cease, and Stiles' breath hitches in his throat as Derek's tongue laps at a smallish cut, his lips closing around it once he senses that it's been properly cleaned and is ready to be closed.

This time when Stiles wriggles beneath him, it isn't to get away, and Derek's eyes snap open, his lips hovering over the second to last tear in the teen's skin as he stifles a groan, because Stiles is rolling his hips up against Derek in a manner which he knows is meant to do something other than to coax Derek to heal him. Derek's breath comes in short, heated pants, and he quickly moves onto the last cut, because, with the way that Stiles is writhing beneath him, he won't last much longer.

Stiles rocks his hips upward, causing his ass to rub against Derek's groin, and Derek's tongue pauses mid-lick, but then he closes his eyes, and allows Stiles to guide this, rocking his hips along with the teen whose movements are jerky and unpracticed. The tip of his tongue roots into the final cut, even as he bears down on Stiles, his dick pressing into the crack of the teen's jeans-clad ass.

"Uhnng," Stiles gasps, and if Derek's mouth wasn't otherwise occupied with the remaining cut, he'd be right there with him.

The teen shifts backwards, rubbing along the shaft of Derek's clothed erection, stimulating a throaty growl from the werewolf who had not anticipated any of this. His memories of healing Kate are tainted by what he's learned since, and are interspersed with what he recalls of the fire that stole his family and turned his uncle into a monster. The memory doesn't evoke anything sexual, and it was nowhere near as intimate as this.

Derek's lips linger on Stiles' back, peppering it with kisses, and he strokes the teen's spine with his tongue long after the cut has been healed. Stiles snakes the hand gripping Derek's wrist beneath him, guides Derek's hand below the waistband of his jeans and Derek shifts them, pulling Stiles upward, pressing the teen's back against his chest so that they're sitting upright and he's got better access to the teen's swollen dick, unzippering boy's jeans and letting it pop free of the constricting material.

He's never done this before, and he doubts that Stiles has either. It's a case of the blind leading the blind, even with their age difference, and Derek's well aware that he's five years older than Stiles, and how ironic all of this is.

"Stiles, I…"

Derek's words are cut off when Stiles twists his neck, and mashes his mouth against Derek's. The kiss is sloppy – way too much teeth and tongue – at first, but then as Derek wraps his fingers around Stiles' erection and begins to pet and stroke it, much in the way he would handle his own dick, and to fondle the teen's balls, the kiss deepens, becomes a series of shared breaths and panted exclamations.

Derek's dick is still pressed into the hollow of Stiles' clothed ass, and as Derek strokes Stiles' dick, the teen rubs back against him, creating friction that's wreaking all sorts of havoc on Derek's system. A spectacular series of bright, colorful lights spark behind his closed eyes, making him dizzy, and he's chuffing like a steam engine.

The slickness of pre-cum coats his fingers, and Derek rubs the substance between his palms before resuming his ministrations, using the natural lubrication to help increase his pace. And, as they both establish a rhythm of stroke, thrust, rub, buck, which complements their twinned heart rate, Derek finds himself lost in the moment. Right now there is no one and nothing else; just him and Stiles and the uncoordinated tempo they've established.

With a sharp cry and a panted moan, Stiles comes, seed bursting upward, coating his sweat slicked chest and spraying the ceiling. Derek comes seconds later, expelling a quiet susurration of air against Stiles' ear, and riding out his orgasm with an arm wrapped around Stiles' chest.

They both collapse, Stiles falling flat on his stomach, and Derek moving so that he doesn't land on top of Stiles, because he doesn't need a repeat of what just happened, as amazing as it was. As he lies there, panting beside Stiles, he tells himself that the only reason it happened, is because he hasn't been laid in a really long time.

"That was," Stiles murmurs, "that was…I don't know what that was, but it was pretty damn amazing, and good, and your hands, they need to be declared something, something , I don't know, something that I don't have words for right, because they are literally mind-blowing."

Stiles reaches for his wrist again, fingers grazing along the pulse point, reigniting the fire his touch had initiated the first time Stiles had grabbed his wrist and held on while he healed him. Stiles is watching him out of the corner of his eye with something akin to a mixture of love and hero worship, and Derek wants nothing more than to get up and leave, or maybe stay forever.

Stiles blushes and Derek blinks, because the teen's cheeks are flushed, and then Derek shifts so that he can see Stiles' back. Stiles' back is completely blemish free, save for a barely there set of reddened teeth marks that, though he doesn't recall making them, won't take a ballistics team to identify the owner of, and they'll be gone by tomorrow anyway. it's just as Derek had envisioned it, even the bruises are gone.

He absentmindedly rubs a thumb along Stiles' shoulder blades, and then lifts up on an elbow. It's time he left. Stiles' eyelids are closing, he's got a sated, pain free look on his face, but when Derek makes to leave, the teen catches at his wrist, pulls him down with surprising force and props an eye open.

There's just the right amount of glare in the look that Stiles gives him, though there's tiredness in it as well. It reminds him of his sister, Laura, the ultimate she-wolf. He'd just as soon cross an Argent on a bad day as her, and apparently now, a jilted Stiles.

"Uh-uh," Stiles says around a yawn, "you, big, bad wolfy boy, aren't going anywhere. Not until we've talked about the amazing power of your healing lips. But first I need sleep, and then we'll talk, or maybe we'll just engage in mindless sex again, because, hello, you've certainly engaged the interest of my teenage hormones here, they kind of want more, and," Stiles yawns again, "and, we probably need to talk about the whole Peter thing."

Derek catches just the faintest hint of fear in the way that Stiles' eye widens just a little and his heart skips a beat when he mentions Peter's name. The way the teen's fingers close tight around his wrist and then loosen a little, also communicate his fear louder than words ever could.

He finds himself nodding in spite of himself and then coaxing Stiles to sleep with quietly murmured words of reassurance. He doesn't know when sleep claims him, but, in the morning, the sun is peeking in on them through crooked blinds. Derek's got an armful of Stiles –both of his arms are wrapped possessively around the teen's waist – and Stiles has one leg between Derek's, the other's perched on the top.

Stiles cracks an eye open, snuggles closer to Derek, and smiles. "We're a human-werewolf sandwich," he mumbles, even as his eye closes and his breathing evens out into sleep. His heart beat's back to normal, a little on the quick side, as is everything that Stiles does.

Derek knows that he should leave now, while Stiles is still very much asleep. If he plays it just right, he can slip free of Stiles' grip without the teen being aware of it. Though Stiles' fingers are still resting along the pulse point on the inside of Derek's wrist, there's no real pressure behind the hold Stiles has on him, just a curling of fingers, and that burning sensation that Derek really doesn't want to examine right now, if ever.

But, as Derek starts to execute his great escape, something stops him. He frowns, because, at first he isn't sure what it is that makes it impossible for him to leave, because Stiles is safe, he's healed and whole, and his father could walk in on them at any moment which would not be good. He really should leave, but then it registers to him why he can't, and he freezes. Stiles' heartbeat has changed, it's slower, steadier, and identical to that of Derek's, something that only happens, that Derek's aware of, between pack mates.

The thought of Stiles being pack, let alone pack mate, scares him, because he's never experienced anything like this before. He's only heard of it, witnessed it between his parents, and thought that if he was lucky, maybe it would happen to him someday, that is, until the fire happened, then he'd known that his life would never be what his parents had. He'd never know love; never have someone who'd match him so perfectly – the light to his dark, the ying to his yang. Stiles is light and love and truth, where Derek is darkness and anger and secretive.

Stiles inches closer, somehow, tightens his grasp on Derek's wrist, and, in sleep, pulls it up to his lips and kisses it. The intuitive action sends a thrill through Derek, makes him smile as it disperses some of the darkness that had begun to form, like a cloud, in his mind – thoughts of Kate, the fire, Peter.

With Kate it had been all about lust and teenage hormones, and though there are teenage hormones involved this time as well, and lust, it's different because it's Stiles.

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Works Cited:

Davis, Jeff, prod. _Teen Wolf_. MTV, Television.

Mech, L. David. 1999. Alpha status, dominance, and division of labor in wolf packs. Canadian Journal of Zoology 77:1196-1203. Jamestown, ND: Northern Prairie Wildlife Research Center Home Page. (Version 16MAY2000).


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